Hgst Netherlands, B.v.

Maxtor Corporation

Drover, Inc.

Timothy John Everett

James Bowling French, Jr

Gary Allan Herbst

David Timothy Flynn

Jonathan Darrel Coker

Thomas O Melrose

Anthony Edwin Welter

Asif J Ahmed

William Gary Creech

Jonathan Darrell Coker

A location and governance system and method for light electric vehicles that includes on-board sensors and receivers for providing readings used to compute absolute and relative vehicle position information, and combining the absolute and relative position information to compute a determined vehicle position, and a current surface type being traveled on by the vehicle. Governance commands for the vehicle can be generated based on the current surface type. Positioning system receivers, inertial measuring units, cameras and other sensor can be used. Vibration analysis, image processing, transition detection and other methods can be used to determine vehicle position and surface type, and spatial databases and other resources can be used. Determining a current surface type the vehicle is travelling on can include determining whether the vehicle is traveling on a sidewalk.

Precision localization and geofencing governance system and method for light electric vehicles

Disk drives with servo systems are described that include a servo ID pattern (SID) with a SAM field, as well as, one or more Integrated Servo sequences designed to provide a redundant sync mark function. The write-to-read gaps are omitted before selected servo sector SIDs. For example, write-to-read gaps can be omitted before alternating servo sector SIDs. When in write-mode that allows writing an extended user data sector without a write-to-read gap, the servo system delays the servo gate assertion with respect to the following SID to accommodate the absence of the write-to-read gap, which means that the SAM field cannot be read, but the Integrated Servo sequence(s) can be read and detected by the digital filters. Embodiments of the invention include sync mark timing for each SID (not just every other SID) even when writing extended user data sectors by using the Integrated Servo sequences to provide a sync timing function.

Disk drive with servo system providing time-syncing for gapless sectors

Disk drives are described that include a hybrid servo patterns in which the augmented servo burst fields, which can be Integrated Servo sequences, that provide the PES and also supply additional information such as a SAM, LSBs of the track identifier (TID), sector number, depending on the specific embodiment. Embodiments without write-to-read gaps before the servo sector SIDs are described. The augmented servo burst fields can be read after gapless writing of the preceding data area. For seeking operations the needed bits of the TID without having to detect or decode the Integrated Servo sequences or other augmented servo burst fields. Depending on the embodiment all or the most significant bits of the track identifier can be obtained during seeks by reading the TID fields passing under a read head as the read head moves across tracks without having to detect or decode the Integrated Servo sequences.

Servo systems with augmented servo bursts

Disk drives are described in which the conventional write-to-read gap is omitted in selected sectors which frees up space that can be used for other purposes including writing a higher number of bits in the user data area in the gapless selected sectors. Alternative embodiments can use the additional space for servo information such as a repeatable run out (RRO) field. Conventional servo sector SID formats can be used for both gapped and gapless SIDs, which means that during seeking and reading operations full SIDs can be read for every wedge. The tradeoff for being able to write data much closer to the gapless SIDs is that the servo system does not detect the SAM or read the TID in the gapless SIDs during write operations.

Disk drive with a subset of sectors with reduced write-to-read gap

A method of reducing microjog errors in a disk drive having a data recording disk with data tracks and a transducer head positionable on the tracks. The head includes a writer element offset from a reader element. To reduce microjog errors, track squeeze is measured at a number of locations across the surface, wherein the squeeze is due to mis-positioning of the track relative to neighboring tracks. A microjog distance for the destination track is provided, and a microjog correction value based on the measured track squeeze is calculated. The correction value is applied to the microjog distance to obtain a corrected microjog distance that reduces microjog errors due to track squeeze.

Method to compensate for microjog error induced by localized track squeeze

A PES linearization scheme using small excitation bode measurements is provided to account for non-linearity characteristics during measurements of head element positions so to generate a more accurate read and write operation by a head element of a disk drive assembly. The PES linearization scheme of this invention provides making gain measurements as the head element moves across the track, and then integrating the result to get a relative PES profile. By then finding two points on the profile a known distance apart, we can multiply the profile by the appropriate gain factor to get an absolute PES profile. This profile can be then be used as a look up table to convert raw PES numbers into actual position.

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Niwot, CO, United States of America

Timothy John Everett